package huawei.exam1;

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

/**
 * @author : Rookie
 * @description : 字符个数统计
 * @date : 2022/12/16
 */
public class HJ10 {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String input = scanner.nextLine();
        Map<Character, Integer> hashMap = new HashMap<>(input.length());
        for (int i = 0; i < input.length(); i++) {
            char key = input.charAt(i);
            if (hashMap.containsKey(key)) {
                hashMap.put(key,hashMap.get(key) + 1);
            } else {
                hashMap.put(key,1);
            }
        }
        System.out.println(hashMap.size());
    }
}
